I've been using Outlook 2011 for Mac for several years. Checking numerous IMAP email accounts with no issues. All of a sudden towards the end of Oct it's started acting up.

It only occurs on my Gmail accounts.

An email will arrive after the first initial sync, it's marked as unread.

After the next sync, it will mark it as read regardless if it's been read or not.

All other non-Gmail accounts are working fine. The issue has only affected Gmail.

I've created a new identity and it works the same way with it as well.

I'm also using other devices to check the same Gmail accounts and they are working correctly. If the email is left unread it says unread. If I read it and then decide to mark it as unread, it will do this and stay unread until read again. All is good there on the other devices.

Only when Outlook is ran and the second sync is made will it mark Gmail emails as read regardless.

During this I also began seeing this error within Outlook for my Gmail accounts.

"Outlook cannot find the server. Verify the server information is entered correctly in the Account Settings, and that your DNS settings in the Network pane of System Preferences are correct.

Error Code -3170"